


An Unexpected Experiment

by Gothythekiller



Category: Bleach
Genre: Aizen Sosuke Being a Bastard, Angst with a Happy Ending, Central 46 Are Assholes, Gen, Hollowfication, Light Angst, Not Canon Compliant, Poor Kisuke, Visored Urahara Kisuke, i think, light Violence, not much but still
Language: English
Status: Completed
Published: 2021-02-16
Updated: 2021-02-16
Packaged: 2021-03-18 03:20:22
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,993
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29482848
Author URL: https://archiveofourown.org/users/Gothythekiller/pseuds/Gothythekiller
Summary: During the Pendulum Arc. Kisuke goes instead of Hiyori because of a bad feeling, and he ends up regretting it. Aizen, however, does not. In fact, even though he might not show it, he's extremely pleased with the outcome.
Kudos: 11





	An Unexpected Experiment

**Author's Note:**

> First Bleach fanfiction I ever wrote, as well as the first I've ever posted. I want criticism, no need to be gentle. Also, a slight warning, I use a bit of dirty language, but not much.

Once the representative from Squad 9 had left, Kisuke felt the urge to force his lieutenant to go to Kensei’s area to retrieve the reishi particles, but he knew it would end in disaster for her. He had an inkling in the back of his mind as to what was going on, and he would be damned if he brought that upon her. So instead, he sent her to Shinji with a false order to watch lieutenant Aizen about a rumor he had heard, while he himself traveled into the Rukon district, clad in one of his new inventions (a cloak that blocks one’s reiatsu, just in case), as well as camera of his own making to record his findings. When he got there, he was greeted by a deserted campground. He was about to begin searching for his friend when his world was suddenly blanketed by darkness, and all of his perceptions dulled down to nothing (minus his sense of touch). Now, Kisuke never panicked, and now was no exception, as he raised Benihime high into the air and let her destroy to her heart’s content. He watched curiously as the dark bubble ripped itself apart, revealing a heavily wounded Kaname, one of Kensei’s most trusted seated members. 

“Well well well, would ya look at this. I thought you were more loyal than that…” In his mind, he heard Benihime screech his name, and dodged Gin’s attack by a hair. “Oh, you’ll find he is very loyal,” a mocking voice spoke from the shadows, drawing the blond’s attention, “just not to Kensei.” Kisuke growled low in his throat, his anger pulsing through his body, giving him strength. “Stop being a coward Aizen! Show yourself, now!” His trusted zanpakuto once again warned him of the upcoming attack, and the sword instead lodged itself into his camera, causing him to curse while Sosuke chuckled. “Now, how is it you keep avoiding our attacks? I should be completely hidden from you.” The scientist shrugged, not willing to give up his one trump card just yet. 

“Beats me. Maybe you just suck at sneaking around.” He began to turn, a comeback on his tongue, when he saw something in his peripherals that gave him pause. When he fully saw what it was, he froze. Before him laid Kensei and Mashiro, Hollow masks covering their faces. “You didn’t…” He whispered, eyes wide in recognition, and thinly veiled terror. He numbly dodged Kaname’s next attack, not looking away from his comrades. “I see you recognize your old hypothesis. That’s good. If I’m being honest, I hoped you would be the one to show up. Your genius is one of a kind, and on top of that, your strength is nearly unparalleled. Imagine the power you could gain through Hollowfication!” A shiver traveled down his spine, and he quickly spun around to face Aizen once more. “What’s your goal here?! What reason could you possibly have for Hollowfying these Soul Reapers?!” He smiled a truly evil smile, and in that moment, Urahara recognized true evil for the first time. 

“To use as test subjects, of course.” Neither of them saw Shinji and Hiyori hiding in the trees, but Tosen could sense their reiatsu, and used his Shikai to knock them out. Kisuke quickly looked in their direction, and felt his blood chill. “No… Why did they…?” He turned to face Aizen again, needing answers before he left. “How did you even know how to do this? I never wrote down specifics!” Aizen was suddenly gone from in front of him, and he barely dodged his attack from behind, Benihime practically vibrating in her sheathe. “My zanpakuto is named Kyoka Suigetsi, and it is not actually a flowing water based zanpakuto. Its real power is perfect hypnosis.” The realization dawned on him suddenly. 

“You completely hid yourself from me, and read through my notes. That’s how you found out.” “Bingo. See, I told you you were a genius. It was the easiest way to figure it out.” He paused for a second, the dark look in his brown eyes getting darker still. “Though, I did wonder, how was it you figured it out? I was only watching you because I didn’t want to draw any attention through sudden disappearances. Did you use the Soul Reapers in the Maggot’s Nest to further your study?” The blond snarled at the accusation. “Of course I didn’t! I learned how to through calculating different possibilities for 30 days straight!” The man laughed. “Of course, that sounds so much more like you.” 

He was gone again, and Benihime warned him of his true location, giving him time to flash step away. He was hyper aware of his surroundings, knowing he was cornered by three enemies, one of which could actually be anywhere else without him knowing, plus his unconscious friends laying around him. “Well, what are we to do now Aizen? He’s as jumpy as a cat.” Gin snarked, zanpakuto in hand and pointed at Kisuke’s back. Tosen was silent, watching over Shinji and Hiyori, but not attacking them (not yet anyway). “Turn those two.” He commanded, and Kisuke tried to flash step over to them, but Aizen was suddenly before him, sword pointed at his chest, and Gin’s was slowly extending towards his back. He was forced to watch as two more of his friends were turned, though at least they stayed sleeping for the painful process. He began to shake, though not from fear. 

“Damn you Aizen. How could you?” The man chuckled. “I can because I forsake my morals long ago. I have my own ambitions, and to reach my goals, I need you out of the picture. Everyone else are simply failed experiments. And now that I know it works,” he reappeared behind him, and he drew his own zanpakuto to parry the blow, narrowly dodging Gin’s shikai before striking back at Tosen. They danced like that for what felt like eternity, until Love, Rose, Lisa, Hachigen, and Tessai flash stepped onto the scene. Kisuke’s grey eyes widened, and he froze for a moment. “Run away! Leave while you have the chance!” He shouted, getting their attention. They did not heed his warning however, Rose rushing towards Hiyori and Shinji while Love ran over to Kensei and Mashiro. The remaining three stood in place, glaring at Aizen. 

“What’s going on here Lieutenant Aizen? Why is your captain injured?” Lisa didn’t get her answer, because the four Hollowfied Soul Reapers awoke with loud screeches that echoed for miles around. Rose and Love jumped back, confused and frightened by why their friends had Hollow masks. Kisuke growled again before flash stepping over to them. “What did I just tell you idiots?! Get the Hell out of here!” He swore under his breath when Gin struck at him, letting Benihime wreak havoc on the three. The first to strike was Kensei, who used his large, heirro covered hands, to try and strike Kisuke down. Rose got in the way though, and parried the hit, with difficulty. 

“What happened to them Kisuke?” Tessai asked, hands moving to try and create a strong barrier. “It’s called Hollowfication. Aizen needed test subjects. I got here too late to help Mashiro and Kensei, and I tried to help Shinji and Hiyori, but I failed. That’s why I’m trying to get you to leave.” His concentration finally broke, allowing Kaname to shoot forward. While the Squad 12 captain recovered, Lisa held Tosen off to the best of her ability. Unfortunately, while everyone was distracted fighting their opponents, Lisa got stabbed by the blind Soul Reaper, and the reishi began to form over her face immediately. “Lisa!” Love shouted, giving Gin the opportunity to slash him. Tessai and Hachigen had used Kido to keep their old comrades down, but it was easier said than done with Shinji, who was powerful enough to force Hachigen’s spells off of himself, but fell when Tessai gave it a go. While Hachi’s guard was down, Aizen stabbed him in the back. 

“Hachigen!” Tessai shouted in anguish, shooting Kido after Kido at the Lieutenant. Now it was only Rose, Tessai, and Kisuke still in the game. Unfortunately, it didn’t stay like for long, with the long haired blond getting cut down not long after the pink haired man. “Tessai, go on and report this while you still can. And don’t worry about me, I’ll be fine.” The dark skinned man seemed extremely hesitant, but eventually relented, flash stepping away, leaving the four alone. “That was stupid, getting rid of the big lug while you’re weak.” Gin mocked, his eyes squinted shut like always. Kisuke chuckled, raising Benihime above his head again. 

“You’re assuming I need Tessai’s help to deal with a non-seated, a 5th seat, and a Lieutenant?” He laughed, with a tinge of insanity, enjoying the hesitation on their faces. “Oh, you children don’t have any idea who you’re facing.” He got all the laughter out of his system, before giving them a blank look. “Scream, Benihime.” He slashed downward, and a large eruption of red energy rushed at them, and even when they dodged, they were left with small gashes on their bodies, except for Aizen, who appeared to have vanished once again. He felt Sosuke materialize behind him, and called out, “Blood mist shield!” The attack was blocked by a red shield, which didn’t dematerialize no matter how many times the brunette slashed it. He raised his sword once more, a grin on his lips. 

“Razor, Benihime!” This time, the pair found themselves unable to fully dodge, and their wounds were deep. Kaname had to drop his sword to stop the bleeding in his arm, while Gin held onto it tight while gripping his leg. Kisuke then turned to face Aizen, who seemed slightly frustrated by the shield. Just when he felt like he had won, his sword warned him a second too late, and he watched in horror as his side was cut open by the real Aizen, who had a serene smile on his face. “You did well Kisuke, but not well enough. You may have defeated Gin and Kaname, but you will never defeat me.” He walked over to his subordinates, and after hefting them up, began walking away. Urahara could feel the reishi flowing through him, and calmed his emotions before they could speed up the process. “You may have won now Aizen, but I swear on my honor as a Soul Reaper, I will beat you one day.” 

He then collapsed onto his knees at the feeling of his mask sluggishly forming. He grasped at his chest, and was relieved that there was no hole forming. Then came dread, when he heard people running towards his location. His hands began to shake, but he shoved the fear of death down, and began to remove everyone’s masks instead, knowing it would be safe to do so, and it would help them regain themselves when they awoke again. Just as he ripped off Rose’s mask, he heard Yoruichi gasp. “Kisuke! Are you okay?!” He heard her run towards him, and he held up his palm. She stopped, but seemed confused. “What’s wrong Kisuke?” He took a deep breath before turning to face everyone, mask half formed, and side bleeding, surrounded by broken off Hollow masks. 

There were gasps from the rest of the captains and lieutenants, but he was only watching Yuroichi and Tessai. “Kisuke… How did this happen?” He laughed harshly, ignoring the reishi for the moment. “I got too cocky… I thought I could defeat them, and for the most part I did, but Aizen’s ability is a cheat! I mean, perfect hypnosis? How do you defend against that?!” He took a deep breath when the mask began to speed up again. “Anyway, turned out he was in front of me, and he got my stomach, and now I’m Hollowfying, just like all the others, and the worst part is that I couldn’t help them properly. Not even my own lieutenant.” He sighed out again, not facing anyone. He felt Tessai grab his shoulder, and was surprised at how upset the man looked. 

“I knew I shouldn’t have left you alone. I should’ve stayed to help you.” The pale blond patted his arm with a small smile. “It’s better that you got the others, because you might’ve become like me if you stayed, and this way, I can’t be framed. I know that’s what Aizen wanted to do, it was obvious.” He paused when the Head Captain began walking towards them, and they all bowed in respect. “Kisuke Urahara, are you certain it was Lieutenant Aizen that did this?” He nodded. “Yes sir. His ability is to hypnotize people, but he didn’t use it much in our fight. If you saw a different Aizen, it was his ability, sir.” The old man grunted, before turning to Shunsui. “You saw Sosuke, did you not?” The man shrugged. 

“It looked like him, but he didn’t talk, and he looked weirdly solemn, so who knows. I for one believe Kisuke though, kid’s smart.” His remaining eye twitched at being called a kid, but once again forced down his emotions to keep the process slow. Ukitake stepped forward, looking concerned. “How is that your… mask isn’t progressing faster? I would’ve assumed it would happen like a normal Hollows…” Kisuke ran his fingers over the reishi with disgust. “It’s because I’m keeping my emotions in check, and I’m conscious.” He pointed to Shinji and Hiyori. “They were unconscious when they were turned,” then he pointed at Hachigen, Love, Lisa, and Rose, “and they were in emotional distress caused by the battle and at losing their comrades, so their masks formed quickly. A Hollow’s mask is near instantaneous because they had been over emotional for years, and it was suddenly released. Or that’s my hypothesis anyway.” He shrugged, slightly perturbed by the growing mask. 

“Why did you remove their masks?” Unohana asked, looking at Lisa’s wound. “Because if I left it on, there was a chance they may go berserk when they awoke, and I really don’t want anyone to get hurt when it can be easily avoided.” His voice was changing, and he was beginning to feel anxious. “The only reason I haven’t removed mine is because it’s dangerous to remove it before it’s finished forming.” Yoruichi began to laugh suddenly, making him jump. “The Hell’s so funny?” She snorted before answering, pointing at his mask, “It’s just, your mask looks stupid!” She began to cackle, even doubling over. At the mention, Tessai began to chuckle under his breath, and so did a few of the others. He was confused, because he couldn’t see it.  “What do you mean? I can’t exactly see it.” Unohana, bless her heart, handed him a mirror, and he gratefully took it. When he saw his reflection, he froze for a second, before exploding like his friends knew he would. “Why the Hell do I have a girl mask?!” It was even funnier with the two-toned voice, and soon everyone was laughing, but it felt… fake. 

He didn’t realise why until he was awoken by a shake. He sat straight up, hands on his face, hoping it was all a dream. When he felt no mask, he almost cheered, before the pain in his side hit him, and he realised that it wasn’t a dream. He looked up and saw Tessai and Yoruichi standing over him, both looking concerned. “When did I fall asleep?” He quietly asked, looking down at the floor. “Not long after you removed their masks.” Tessai answered. “Your own mask formed pretty quickly after you passed out, and then we had to fight you and remove your mask, and use a forbidden technique to get everyone here. What were you thinking, sending me away like that?!” Kisuke shrugged. 

“I didn’t want you to get turned, and I hoped that, maybe if you told everyone about Aizen, we wouldn’t be killed.” The woman scoffed. “You’re lucky he went to get me instead. On the way to the Head Captain, he saw motherfricking Aizen, or at least a fake Aizen, and knew immediately that no one would believe him.” He groaned into his hands. “This sucks balls! I hoped this was a dream, but no. Maybe nothing of value will happen today.” Suddenly, the doors were forced open, and the three were surprised to see the Stealth Force at his door. “Woah! What the Hell’s going on here?!” Yoruichi demanded, looking surprised when Soi Fon pushed her way up front. She glared at Kisuke with pure hatred. “Lady Yoruichi, I have told you time and time again that he is not the good person you think he is, and I finally have proof.” His grey eyes were wide with mock confusion. 

“What do you mean? What do you think I did this time?” He grinned good naturedly, a pit growing in his stomach. “We have evidence that you were doing Hollowfication experiments!” She then turned to face Tessai. “And you used forbidden arts to move the Soul Reaper test subjects!” Before any of them could begin to try and tell her the truth, they were hauled away. When they reached the Central 46 chamber, Kisuke was using all his willpower to keep his mask from manifesting. The hearing was as one sided as it usually was, and when he heard he was being sent to the human world, he couldn’t find it in himself to care. When Tessai was sentenced to be kept in a cell, he figured it was better than his own sentence, though he felt upset that he had dragged his best friend into his mess. 

“And finally, Captains Shinji Hirako, Rose Otoribashi, Love Aikawa, and Kensei Muguruma, and Lieutenants Mashiro Kuna, Hiyori Sarugaki, Lisa Yadomaru, and Hachigen Ushoda, will be disposed of as Hollows immediately.” Suddenly, it felt like his whole body went cold, and his mind screamed with a protective instinct he didn’t know he had. He stood up sharply, his chair screeching as it flew back. “Wait! You can’t just kill them! They’re still Soul Reapers!” The guards manhandled him back into his seat despite his struggling. One of the members seemed especially infuriated by his claim. “Of course they’re not! We saw their masks! They are Hollows, and will be treated as such!” Kisuke clenched his fists in anger, and in his mind he could hear his Hollow sing to be let out, to prove them wrong. He shoved it away as hard as he could. 

“I’m the one who did research on this topic! As long as they are able to defeat their Hollows in their inner world, they will stay the same as always! They would be able to use the powers of a Hollow to make themselves stronger!” He was once again pushed down, and the Central 46 continued to deny his claims. He was beginning to get desperate, and that was when his own Hollow took the chance to take over. The guards jumped away quickly as Kisuke’s body was overtaken by crimson energy, and soon mad cackling could be heard from within. Tessai felt fear course through his body at the double tone his friend’s voice had taken, and knew that was no longer his friend for the moment. When the energy subsided, instead of having a normal looking Kisuke, he was instead wearing half of a mask, which looked similar to a woman’s face on the one fully manifested side, and it was slowly growing, bits of reishi merging together. He was still chuckling to himself, eyes closed for the moment. “Kisuke Urahara, what is the meaning of this?!” Finally his eyes opened, revealing black sclera and piercing white eyes. 

“Oh, you mean this new power-up?” He shrugged, and it looked so much like Kisuke it scared Tessai. “Nothing much. I was only given the opportunity to appear because you put King under so much distress, saying you were going to kill his little friends because they were different. Even though it was NOT King’s fault, he takes the blame, of course, because he was unable to save them.” He mocked a sigh. “Well, I guess it doesn’t matter all that much, seeing as I’m going to kill you.” He raised Kisuke’s sword, and just as he was going to use his Scream technique, his other hand reached upward and grasped the mask tightly. The Hollow sputtered and tried to fight back, but as soon as the mask was removed, all sound stopped, minus Kisuke’s own labored breaths. He looked up at the Central 46 members who seemed to be in shock and grinned. 

“Sorry about that,” he slid Benihime back into her sheathe, “as you can see, I have yet to conquer my Hollow, and emotional situations like this can trigger it, so please be more sympathetic next time.” He dusted himself off before sitting down again, no longer bothering to keep his emotions hidden. One of the members pointed his finger at Kisuke, who raised a brow. “You turned yourself?! Showing this only proves that you deserve death as well!” Kisuke raised his hand to the right side of his face, feeling the Hollow trying to come free again at the threat. Then, the doors exploded inward and a masked person ran into the courtroom. Everyone was yelling, and Yoruichi took the opportunity to get her two best friends into the safety of the bunker they had created as children. Kisuke finally released his face now that they were out of hostile territory and turned to face the rich bitch he called his friend. “Thanks for that Yoruichi. If you didn’t come get us, my Hollow would’ve acted out again.” 

He had a goofy grin on his face, but she could already see the stress marks forming. She laughed a bit to raise his spirits, before slapping his back, hard. “Now, what’s this I hear about you Hollowfying in the courtroom? The Hell’s wrong with you?!” He grinned sheepishly and shrugged. “I was tense! They said they were gonna kill Hiyori and the others, and my Hollow took advantage of that! And then after I Hollowfied, they gave me death too!” He groaned and rubbed his face. “This whole thing has been a train wreck. How are the others? Are they here?” He raised his head to look around, but he just saw blank desert. Yoruichi snorted and grabbed at the air, and he realized she used one of his first working inventions when she pulled off an invisible tarp, letting him see that they were all still sleeping. 

“It was hard work getting them here, but I managed. Seriously Kisuke, you are a genius!” Somewhere in the back of his mind, he heard Sosuke echo that back at him, but he shook it off. This was Yoruichi, and it was meant as a compliment, nothing more. When he actually looked at them, he frowned in concern. “They should’ve woken up by now. I mean, I think? I woke up normally, so they should as well, I guess.” The woman shrugged. “I don’t know anything about this sort of thing, so you’re on your own.” He poked Shinji, and smiled softly when he groaned in protest. “They’re okay. Probably just exhausted after last night.” He himself yawned before turning to his best friends. “We can’t stay here anymore, and I’m sorry for dragging you into this.” Tessai grinned. “We’re your best friends Kisuke. Even if we hadn’t been dragged into this whole mess, we still would have helped you no matter what.” Yoruichi chimed in, “Of course! Now, I snagged 10 of those stealth gigai you created at the beginning of the ‘people disappearing without their clothes’ thing, so let’s haul ass out of here!” Kisuke beamed, happy to know that he couldn’t have made a better choice for friends.


End file.
